Speaker 1: Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren vog Obam here. If you've ever shared a home
Speaker 1: with a dog, you've probably had the startling experience of,
Speaker 1: while minding your own business, having a cold, wet nose
Speaker 1: thrust into your skin like a friendly ice cube. It's
Speaker 1: your pup's way of getting your attention, and it's an
Speaker 1: old wives tale that's such a wet nose is a
Speaker 1: good thing because it supposedly means your dog is in
Speaker 1: good health. But this idea has no basis. In fact,
Speaker 1: whether a dog has a wet nose is not a
Speaker 1: signal one way or another of health. But why are
Speaker 1: dogs noses sometimes dry and sometimes wet. The short answer
Speaker 1: is that dogs sometimes lick their noses, But the catch
Speaker 1: is that no one knows for sure why they do that.
Speaker 1: One theory suggests that because dogs are always licking their noses,
Speaker 1: their saliva helps paint their schnas with the mucus produced
Speaker 1: in the nostrils. As a result, all that mucus looking
Speaker 1: improves a dog's ability to smell things. Let's break down
Speaker 1: how that works. When dogs sniff the air, and they
Speaker 1: are always sniffing the air, they inhale tiny suspended particles.
Speaker 1: These particles get trapped in their nasal mucus, which helps
Speaker 1: the dog figure out what they're smelling. As a dog
Speaker 1: licks its nose, it picks up some of these scent
Speaker 1: Latin goop. The tongue then brushes against an olfactory gland
Speaker 1: on the roof of the mouth, which helps our four
Speaker 1: legged companions figure out exactly what they're smelling. Another reason
Speaker 1: some have suggested could be that a wet nose helps
Speaker 1: keep a dog cool in warm weather. When we humans sweat,
Speaker 1: the perspiration are sweat glands produce evaporates off of our skin,
Speaker 1: cooling us down. Dogs, however, do not sweat. That's because
Speaker 1: they have no sweat glands except from the bottom of
Speaker 1: their pop haads. Instead, they pant to cool off. However,
Speaker 1: a dog's nose, unlike the rest of its body, is
Speaker 1: not covered in fur. It also brims with blood vessels.
Speaker 1: When a dog licks its nose, the theory suggests it's
Speaker 1: cooling itself down as it's saliva like human sweat, evaporates
Speaker 1: that leaves the surface area of the no cool along
Speaker 1: with the blood circulating in and around Fido's snout. Consequently,
Speaker 1: cooler blood flows the dog's head and body, keeping our
Speaker 1: best friends a little bit cooler. But then, why are
Speaker 1: dogs noses often dry? A few factors can lead to
Speaker 1: less licking. Touch your dog's nose in the morning, chances
Speaker 1: are it'll be dries the sahara. That's because as a
Speaker 1: dog sleeps, it rarely licks its nose, and certain breeds
Speaker 1: like bulldogs and pugs, have noses that are mostly dry.
Speaker 1: Age also tends to make a dog nose dryer. The
Speaker 1: bottom line is that if your dog has a dry nose,
Speaker 1: chill out. The dog isn't sick. Wait a few hours
Speaker 1: and it will be wet again. Oh and a bonus
Speaker 1: pup nose fact. Have you noticed that your dog has
Speaker 1: slits on the sides of its nose. There's a reason
Speaker 1: when dogs exhale, they do so out of those slits.
Speaker 1: That's so that the exhaled air does not mix with
Speaker 1: the scented inhaled air, which flows into the nostrils. Today's
Speaker 1: episode was written by John Paritano and produced by Tyler Clang.
Speaker 1: For more in this and lots of other startling topics,
Speaker 1: visit our home planet, how Stuff Works dot Com.